ww/test/wcc/989_fnptrcollide_run.c

/*
 * 989_fnptrcollide_run — F7-c7 (#14): nodefnptr must be type-keyed, not
 * name-keyed, so a value ident whose LEAF collides with a fn name is not
 * mis-folded into the fn's TEXT reloc.
 *
 * THE BUG (cat-A silent miscompile, gate-blind): nodefnptr
 * (selfhost/cmd/wcc/cgen.ww) decided whether `&x` (in a static-init / DATAR
 * fold context) was the address-of a top-level fn by NAME — `fnretlookup(
 * c, x.str) != nil`. So `&slot` for a data global `slot: i64` that shares a
 * leaf with a fn `slot` (e.g. an imported `bar.slot`) matched the fn and
 * folded into a DATAR reloc to the fn's TEXT symbol instead of the data
 * symbol. cstage is type-keyed (node_fnptr_sym: type_chase_named(opnd->
 * type)->kind == TY_FN, cmd/w6c/cgen.c:15542) — `slot`'s stamped type is
 * i64, not TY_FN, so it does NOT fold the reloc and the build errors loud.
 * Pre-fix wwstage silently produced a binary (the cat-A divergence: cs
 * loud-fails, ww builds). THE FIX: read the stamped operand type
 * (opnd.type_ chased == TY_FN), aligning wwstage UP — a non-fn operand can
 * never fold to a fn reloc, closing the leaf-name collision by construction.
 *
 * This shape is gate-blind (the corpus never collides a data-global leaf
 * with a fn name on the &-fold path); only this row catches it. The
 * conversion's neutrality on the corpus's REAL &fn static-inits (the
 * #117/#119 reloc machinery) is proven separately by the c7 self-compile
 * byte-id bind (B1/B2 zero-move) — see /tmp/implf7_result.txt.
 *
 * Assertion: the construction must FAIL TO BUILD on BOTH stages (cstage
 * already rejects; wwstage now rejects too — rule-10 align-up). Pre-fix
 * wwstage BUILT it (rc=0) — the row was RED on the pre-c7 binary.
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>

static int
runwait(const char *cmd)
{
	int rc = system(cmd);
	if (rc == -1) return -1;
	if (WIFEXITED(rc)) return WEXITSTATUS(rc);
	return -1;
}

/* build_must_fail — write a bar/ module (fn `slot`) and a main.ww that
 * declares a data global `slot: i64` plus `let fp: *i64 = &slot`, then
 * `drv build -I bar main.ww`. Returns 0 when the build correctly FAILS
 * (the leaf-name collision no longer diverts &slot into the fn reloc),
 * non-zero when it wrongly built. */
static int
build_must_fail(const char *drv, int tag, int *cleanup_failed)
{
	int pid = getpid();
	char dir[96], bard[160], p[224], cmd[1024];
	int rc = -1, setupfail = 1, cleanfail = 0, bard_owned = 0;
	*cleanup_failed = 0;
	snprintf(dir,  sizeof dir,  "/tmp/fnpc_%d_%d", pid, tag);
	snprintf(bard, sizeof bard, "%s/bar", dir);
	if (mkdir(dir, 0755) != 0) return -2;
	if (mkdir(bard, 0755) != 0) goto cleanup;
	bard_owned = 1;

	snprintf(p, sizeof p, "%s/bar.ww", bard);
	FILE *f = fopen(p, "wb");
	if (!f) goto cleanup;
	fputs("package bar;\n"
	      "export fn slot() i64 = { return 99; };\n", f);
	if (fclose(f) != 0) goto cleanup;

	snprintf(p, sizeof p, "%s/main.ww", dir);
	f = fopen(p, "wb");
	if (!f) goto cleanup;
	fputs("package main;\n"
	      "import bar;\n"
	      "let slot: i64 = 7;\n"
	      "let fp: *i64 = &slot;\n"
	      "export fn main() int = { return (*fp): int; };\n", f);
	if (fclose(f) != 0) goto cleanup;

	snprintf(cmd, sizeof cmd,
	    "cd %s && %s build -I bar main.ww >/dev/null 2>&1", dir, drv);
	rc = runwait(cmd);
	setupfail = 0;

cleanup:
	snprintf(p, sizeof p, "%s/main.sepwork", dir);
	snprintf(cmd, sizeof cmd, "rm -rf %s", p);
	if (runwait(cmd) != 0) cleanfail = 1;
	snprintf(p, sizeof p, "%s/main", dir);
	if (unlink(p) != 0 && access(p, F_OK) == 0) cleanfail = 1;
	snprintf(p, sizeof p, "%s/main.ww", dir);
	if (unlink(p) != 0 && access(p, F_OK) == 0) cleanfail = 1;
	if (bard_owned) {
		snprintf(p, sizeof p, "%s/bar.ww", bard);
		if (unlink(p) != 0 && access(p, F_OK) == 0) cleanfail = 1;
		if (rmdir(bard) != 0) cleanfail = 1;
	}
	if (rmdir(dir) != 0) cleanfail = 1;
	*cleanup_failed = cleanfail;

	if (setupfail) return -2;
	return rc == 0 ? -1 : 0;	/* build must NOT succeed */
}

int
main(void)
{
	const char *bin = getenv("BIN");
	if (!bin) bin = "out/bin";
	char absbin[1024];
	if (bin[0] != '/') {
		char cwd[1024];
		if (getcwd(cwd, sizeof cwd) == NULL) return 1;
		snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
		bin = absbin;
	}

	char cdrv[1024], wdrv[1024];
	snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
	snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);

	int total = 0, fail = 0;

	total++;
	int cleanfail = 0;
	int got = build_must_fail(cdrv, 1, &cleanfail);
	if (got != 0) {
		fprintf(stderr, "fnptrcollide_run[cstage]: %s\n",
		    got == -2 ? "setup failed" :
		    "built ok, expected the leaf-name collision to be rejected");
		fail++;
	}
	if (cleanfail) {
		fprintf(stderr, "fnptrcollide_run[cstage]: temporary cleanup failed\n");
		fail++;
	}
	if (access(wdrv, X_OK) == 0) {	/* wwstage gated */
		total++;
		got = build_must_fail(wdrv, 2, &cleanfail);
		if (got != 0) {
			fprintf(stderr, "fnptrcollide_run[wwstage]: %s\n",
			    got == -2 ? "setup failed" :
			    "built ok, expected reject (#14 — &slot mis-folded "
			    "to the fn TEXT reloc by the name-keyed nodefnptr)");
			fail++;
		}
		if (cleanfail) {
			fprintf(stderr, "fnptrcollide_run[wwstage]: temporary cleanup failed\n");
			fail++;
		}
	} else {
		fprintf(stderr, "fnptrcollide_run: skip wwstage (no %s)\n", wdrv);
	}

	if (fail) {
		fprintf(stderr, "fnptrcollide_run: %d/%d checks failed\n",
		    fail, total);
		return 1;
	}
	printf("fnptrcollide_run: %d/%d ok\n", total, total);
	return 0;
}